Expansion joint in concrete pavements



April 22, 1930 v J. H. KNOX L759239 y EXPANSION JOINT IN CONCRETE PAVEMENTS Filed Feb. 18, 1929 i Patented Apr. 1930 'UNITED STATE-s JEAN H. x'Nox, or `IiALLAs, TE'xAs, AssIGNoB. or ONE-HALE To ASSOCIATED FAC# TOBIES CORPORATION; OF DALLAS, TEXAS, A CORPORATION OFDELAWARE EXPANSION JoNT TN CONCRETE rAvEmENTs f A Application led February 18,1929. Serial No. ,$40,827.r

This invention relates to a means and the pavement and illin method for increasing the effectiveness and endurance of pavement and more particular' ly to provide a dowel bar sleeve, whereby there is provided an pavement. e i

As is well known to those familiar with lthe art of pavement'construction it is'necessary to provide a small space between adjacent portions of a concrete or other pavement to permit the pavement to, expand or contract under weather conditions. This is usually done by leaving a small space in portions of the space' with some expansion joint in the this. manner of construction, however, -no means are provlded for maintainlng the avev ment in true alinement, one portion wit the other, when weather conditions expand or contract the parts.

The present invention providesa means and method forjoining the parts, segments, portions orpieces of pavement in construction so that when expansion takes place the pavement will be permittedto move but remain in "t true alinement,one part with the other, the v result being a perfectly smooth roadway.

While the means and method hereinafter' disclosed are intended mainly for pavement it can be used wherever there is need for an expansion joint in concrete or other materials. .A

In' the drawings forming apart of this specification:

i and sleeve forming a unit,

Figure 1 illustrates a perspective and fragmentary view o a pavement, embodying the invention,

Figure' 2 is a sideelevational view of one of the dowel bars and coacting sleeve, whereby the expansion joint is formed,

Figure 3 is an enlarged side elevational view of a sleeve,

Figure 4 1s asimilar view of a bar, theI bar Figure 5 is an end elevational view q E the sleeve, showing its construction, and

Figure 6 is an end view of the bar.

Proceeding in accordancey with the drawings, wherein specific parts are indicated by numerals, 1 denotes a cylindrical bar, prefervthe pavement parts or sections 3 an Attention is here directed to the construction of the sleeve or tubular element 2. 4This element is formed of a strip of resilient metal,

of longitudinal shape, b y bending the lon'gi.-l 4

tu'dinal sides of the strip over upon them-y selves'as shown in Figure. 5. The sides then are overlapped, the enclosed side o'r portion having a lip 5, bent "at an angle to the cylindrical shape of the sleeve. This lip extends longitudinally of the sleeve and'iprovides a `means for engaging the bar 1, when the bar and sleeve are placed together in `making up a joint in the pavement.

' After thebar is inserted' within the sleeve, this lip 5 is forced along its length against the inner wall of the sleeve. In this manner, the .bar can be moved within the sleeve when movement takes place in the pavement, yet

the `sections of pavement 3 and 4 will remain firmly in alinelnent.y

O f course, /he bar and'sleeve are not restricted to any particular length, but their relative proportlons are such that, as shown in Figures 3 and 4, the sleeve' is somewhat longer than'the bar or rod 2.

In placing the sleeve and bar in the ave-v I ment, a suicient number of sleeves an bars' are connected together and, as illustrated in Figure 1, the assembled units are` spaced across the divisional Line or space 7 and embedded in the concrete or other substance forming the pavement. The bars 1 and sleeves 2 are embedded in the pavement, but that portion of the bar insidethe tube or sleeve will be free to move laterally. l

The invention is not to be understoodas being restricted to the particular form herein shownnbut may be modified to come within the scope and meaning 'o -the appended claims.

What is claimed as'new is: l A 1. `A de .ce for preventing adjoining slabs of concrete and cementitious material yfrom lmoving out of horizontal alinement with each other during expansion and contraction which consists of a tubular member formed by a sheet of metal rolled to form the member, the outer edge of the member overlappingthe inner edge andthe inner edge of the member being bent at an angle on itself v and providing a longitudinal lip; and a rod adapted to lie within the tubular member so thatthe rod will bear against said lip and the interior surface of the tubular member to hold the two parts in a tight embrace; the close contact of the rod and member fixing the two together both before and Iduring construction of the slabs in true relative positions and preventing pre-slipping of the rod and member but permitting the rod and member to move one within the other when the slabs move apart from one another on lexpan- .sion and draw together on contraction.

within said sleeve; said rod being held tightly within the sleeve. and preventing slippage of the sleeve and rod from one another' except s at such time as the joint formed in the sla expands or contracts during weather conditions, whereupon the rod will be permittedto slide withinthe sleeve and the sleeve` to slide over the rod.

3. A device as claimed in claim l, bular member being formed by rolling so that one edge overlaps the other thereby providing resiliency, the overlapping edges being movable upon each other to permit expansion as sai rod is inserted into the member, said member having a smooth cylindrical surface on the outside from end to end.

4. A telescopic unit adapted to be embedded within abutting ends of concrete slabs, comprising a dowel, a sleeve of substantially greater diameter than said dowel and spaced therefrom, andv yielding frictional spacing means for normally maintaining said sleeve and dowel in fixed longitudinal relation before the unit is embedded in the concrete, while permitting relative longitudinal movement of said sleeve and dowel to lallow for expansion and contraction of the concrete after the unit is embedded within the concrete.

5. A device for lconnecting abutting ends of concrete slabs, comprising a plurality of telescopic units adapted to beembedded in aid at the concrete, each unit comprising a sleeve, and a dowel frictionally held within said sleeve and spaced from the Asleeve throughout the principal portion of its perimeter.

-6. A device of the character described comprsing a sleeve having an inturned lip and a dowel tting within the sleeve of substantially less diameter than said sleeve, and frictionally engaged by said inturned lip, whereby slippage of said sleeve and dowel prior to use is prevented, while relative longitudinal movement is permitted when the device is embedded in the abutting ends of concrete slabs to permit contraction and expansion of the slabs.

7. In a devicel for connecting abutting ends of lconcrete slabs, a plurality of sleeves elnbedded in one of said ends and a plurality of rods embedded in the other end, said rod fitting within the sleeves, said sleeves being of substantially greater internal diameter than said rods, and resilient spacing means interposed between the sleeves and rods for normally maintaining said sleeves and rods in fixed-longitudinal relation, while permitting relative longitudinal movement on contraction and expansion of the slabs in which the sleeves and rods are embedded.

In testimony whereof l affix my signature.

JEAN H. KNOX. 

